Finished up a 16666 restoration and couldn't figure out why the oscillation was off center and behaving oddly. Noticed the lower link arm is different on a big motor vs. a small motor early oscillator. Learned something. This particular 16666 someone had put on a small motor link arm which is causing the issue.

Looking to buy or trade for this 'big motor' link arm shown below. For reference I pulled this one off another 16666 I have to show what it looks like in comparison.

I know no-one likes to part ways with these types of items but if you should have an extra I'll buy or trade for it plus owe you several beers at FF.